1. Field of the Invention
The present invention relates to a speaker that can produce excellent sound quality as well as sufficient sound pressure regardless of the power value by means of providing at least one additional annular corrugated plate.
2. Description of Related Art
FIGS. 1 and 2 of the drawings illustrate two typical conventional speakers. As illustrated in FIG. 1, the speaker includes a T-iron 10, a ring magnet 11 mounted around a central protrusion 101 projecting from a central portion of the T-iron 10, a pole plate 12 mounted on top of the ring magnet 11 and spaced from the central protrusion 101 of the T-iron 10, a frame 13 mounted on top of the pole plate 12, a diaphragm 15 supported by an edge 131 of the frame 13, a coil core portion 14 surrounding the central protrusion 101 of the T-iron 10, a voice coil 141 wound around the coil core portion 14 and spaced from the pole plate 12, and an annular corrugated plate 16 which is mounted around and supports the coil core portion 14. The voice coil 141, when energized, generates vibration waves for causing the annular corrugated plate 16 and the diaphragm 15 to vibrate. The annular corrugated plate 16 is provided for showing the bass of the sound. The speaker of FIG. 2 is similar to that of FIG. 1, except that an additional annular corrugated plate 16 is provided.
The damping strength of the annular corrugated plate 16 affects the restoration and the resonance frequency of the coil core portion 14; namely, the effectiveness of oppressing inertial damping by annular corrugated plate 16 affects the power and sound pressure (volume) withstandable by the speaker. Thus, the number of the annular corrugated plates 16 for a speaker depends on the power. A speaker having only one annular corrugated plate 16 shown in FIG. 1 may produce clear sound when the power is low, but the effectiveness of oppressing inertial damping by the annular corrugated plate 16 drops when the power is high, as the restoration force and strength of the annular corrugated plate 16 are insufficient. As a result, the annular corrugated plate 16 overvibrates and the sound quality is lost. On the other hand, a speaker having two annular corrugated plates 16 shown in FIG. 2 solves the problems encountered in high power situation, but the restoration force and the damping are too large when the power is low, resulting in insufficient sound pressure (the volume is too low). The dilemma in sound quality for high power and lower power is a bottleneck to speakers.
An object of the present invention is to provide a speaker that can produce excellent sound quality as well as sufficient sound pressure regardless of the power value by means of providing at least one additional annular corrugated plate. The strength and the restoration force of the whole annular corrugated plate are increased such that the speaker may bear higher power and maintain the volume.
A speaker in accordance with the present invention includes a T-shape iron having a central protrusion on a central portion thereof, a ring magnet mounted around the central portion of the T-shape iron, a pole plate mounted on top of the ring magnet and spaced from the T-shape iron, a frame mounted above the pole plate, a diaphragm mounted to the frame, a coil core portion mounted around the central protrusion of the T-shape iron, a voice coil wound around the voice core portion, a first annular corrugated plate mounted around the voice core portion and spaced from the voice coil, the first annular corrugated plate having an inner section adjacent to the coil core portion and an outer section distal to the coil core portion, and at least one second annular corrugated plate. The second corrugated plate is bonded to an inner side or an outer side of the outer section of the first annular corrugated plate and spaced from the coil core portion, thereby increasing a thickness and strength of the outer section of the first annular corrugated plate for bearing higher power such that the speaker generates clear sound and that the inner section of the first annular corrugated plate generates sufficient sound pressure when a power outputted by the speaker is low. The second annular corrugated plate has an inner diameter greater than that of the first annular corrugated plate.
The diaphragm includes an outer periphery that is bonded to an edge of the frame, and a reinforcing plate is bonded to an outer side of the edge of the frame.
In an embodiment of the invention, a second annular corrugated plate and a third annular corrugated plate are bonded to the outer section of the first annular corrugated plate and spaced from the coil core portion, thereby increasing a thickness and strength of the outer section of the first annular corrugated plate for bearing higher power such that the speaker generates clear sound and that the inner section of the first annular corrugated plate generates sufficient sound pressure when a power outputted by the speaker is low.
Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.